What Is HTPLA?
HTPLA (Heat-Treatable PLA) prints with the same ease as standard PLA — no fancy enclosure or all-metal hotend required — but with one big advantage: once printed, it can be heat-treated (annealed) to dramatically boost its heat resistance and strength. A part that would normally deform around 60°C can hold its shape well past 100°C after annealing, making it a favorite for functional prints, molds, and even car dashboard parts.
What You'll Need
- Your favorite HTPLA filament
- A standard FDM 3D printer
- An oven or dedicated annealing box/toaster oven
- An oven-safe thermometer (don't trust the oven dial alone!)
- A flat, heat-safe surface for the annealing process
Step 1: Dial In Your Print Settings
HTPLA prints very similarly to standard PLA:
- Nozzle temp: 210–230°C
- Bed temp: 50–60°C
- Print speed: Standard PLA speeds work fine (40–60mm/s)
- Cooling fan: On, same as regular PLA
Always check your specific filament's spec sheet since colors and formulations can vary slightly (metallics and glow blends especially).
Step 2: Design with Annealing in Mind
Annealed HTPLA shrinks slightly (often 1–2%) and can warp if wall thickness is very uneven. For best results with functional parts, use consistent wall thickness and avoid tight-tolerance features until after you've tested how much your specific print shrinks.
Step 3: Preheat Your Oven
Preheat your oven to the annealing temperature recommended for your filament, typically 115–135°C (240–275°F). Use an oven-safe thermometer inside to verify — home oven dials are notoriously inaccurate, and overshooting can warp or melt your print.
Step 4: Anneal the Print
Place your print on a flat, heat-safe surface (a ceramic tile or metal tray works well) so it doesn't warp while soft. Bake for about 10–20 minutes depending on part thickness. Thin parts anneal faster; thick or dense parts need longer to heat through evenly.
Step 5: Cool Slowly
Turn off the oven and let the print cool down inside with the door closed or cracked slightly. Cooling too fast can introduce warping or stress cracks. Once it's back to room temperature, your part is fully annealed.
What to Expect After Annealing
- Heat resistance jumps from ~60°C to 100°C+ (varies by brand/formulation)
- Increased rigidity and layer bonding strength
- Slight shrinkage (usually 1–2%) and a subtle change in surface finish/color saturation
Great Projects for HTPLA
Car interior parts, outdoor fixtures, hot-water-adjacent tools, cosplay props that need durability, and functional jigs or fixtures for your workshop all benefit from HTPLA's post-annealed strength.
Shop HTPLA Colors
- Marine Dream Blue Multicolor HTPLA
- Tom's Tangerine Orange Metallic Gold HTPLA
- Nebula Stardust Multicolor HTPLA
- Lab Coat White HTPLA
- Nebula Rainbow Multicolor HTPLA
Tried annealing your own print? Share your results in the comments — we'd love to see how your color held up! 🔥